This invention relates to an improvement in a heat sensitive label for packaging a dry-cell battery.
Referring to FIG. 4, a label 30, which has a label substrate 31 made of a heat shrink film, a printing layer 32 provided on one surface of the label substrate 31, and a pressure sensitive adhesive layer 33 provided on an opposite surface of the label substrate 31, is wound around a dry-cell battery and bonded to the same via the pressure sensitive adhesive layer 33. Instead of a conventional metal jacket, the label of this type is commonly used for packaging the dry-cell battery, since it can be manufactured to be thinner than the metal jacket, and is therefore advantageous in the fact that a dry-cell battery of a larger dimension can be packaged, while maintaining an outer diameter of a finished product of the battery with the label 30 thereon.
For packaging the dry-cell battery with the label 30 thereon, a release paper 34 is usually attached to an exposed surface of the pressure sensitive adhesive layer 33 provided on the opposite surface of the label substrate 31 to prevent the pressure sensitive adhesive layer 33 from bonding to unintentional portions. The release paper 34 is relatively expensive, and requires additional steps, that is, the steps of attaching the release paper to the pressure sensitive adhesive layer 33 and releasing the same therefrom. This may be troublesome and increase the manufacturing cost of the label 30.
Alternatively, there has been proposed a heat sensitive label with an adhesive layer of a heat sensitive adhesive thereon, since the heat sensitive adhesive does not possess an adhesive property until the heat sensitive label is heated to a predetermined temperature. This arrangement eliminates the necessity of the release paper 34 or the like in transportation and storing of the label 30.
However, when activating the heat sensitive adhesive of this type by heat, a printing ink of the printing layer 32 may be damaged by the heat, and consequently deteriorate the appearance of the label 30.
In addition, when the label substrate 31 of the heat shrinking film is heated to an excessively high temperature for activating the adhesive, the label substrate 31 may be shrinked and subsequently deformed and/or wrinkled.
It is an object of the present invention to provide a heat sensitive label for snugly and securely packaging the dry-cell battery in an inexpensive manner.